Swarna K. Ghosh

Centre Director
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Savitribai Phule Pune University Campus,
Pune 411 007
Maharashtra, INDIA
Status: Left

Main Research Areas: The Interstellar Medium, Infrared Astronomy, Astronomical Instrumentation.


Swarna K. Ghosh obtained his B Sc (Honours) & M Sc (Physics) from Kurukshetra University in 1973 & 1975, respectively. He then joined the Tata Institute of Fundamental Research (TIFR), Bombay, for his doctoral studies, which he completed in 1982. He has continued to be with TIFR after this. He also spent 2 years (1984-86) as a Post-Doctoral Fellow of the Max-Planck-Gesellschaft at the Max-Planck-Institut für Extra-terrestrische Physik (MPE), Garching, West Germany. During 2000-01 he spent one year as a Visiting Professor at the Institute of Space and Astronautical Science (ISAS), Sagamihara, Japan. He moved to NCRA, Pune, in early 2010 as the Centre Director, but continues to be associated with the Natural Sciences Faculty and the Department of Astronomy & Astrophysics at the main campus of TIFR (Colaba, Mumbai).

Research description:

My primary research interests lie in the interstellar medium, especially star-forming regions, and in astronomical instrumentation:
The Interstellar Medium
My research broadly aims to understand star formation activity in the Milky Way by probing conditions in massive star forming regions as well as young stellar objects. Different research projects include: (1) Studying the structure of the interstellar medium (ISM) around massive star-forming regions and photo-dissociation regions through mapping of emission in the 158 micron [CII] line, the polycyclic aromatic hydrocarbon (PAH) lines, and the dust continuum. The PAH studies are especially interesting as they are the main source of gas heating in photo-dissociation regions and the atomic ISM, via photo-electric emission. (2) Multi-wavelength (photometric & spectroscopic) monitoring of outbursts in young stellar objects to study episodic accretion on these systems. (3) Detailed studies of the post-outburst phase of McNeil's nebula, an exciting pre-main sequence star which has recently undergone an eruption, illuminating the cocoon of gas and dust that surrounds it. This rare event allows a probe of the late stages of the evolution of a star onto the main sequence. (4) Multi-wavelength investigations of the morphology, physical environment, stellar contents and star formation activity in Galactic star-forming regions, probing the distribution of young stellar objects, their evolutionary sequence, star formation scenarios, etc. (5) Infrared studies of southern Galactic massive star-forming regions, using simultaneous mapping in two far infrared bands at ~150 and 210 micron, using the TIFR 1-m balloon-borne telescope with diffraction limited angular resolution, and supplemented by measurements from the ISO & MSX satellite missions. (6) Using the Midcourse Space Experiment (MSX) data to probe warp signatures in the Galactic disk as well as the spatial distribution of emission in the Unidentified Infrared Bands in the Galactic plane.
Astronomical Instrumentation
My other main research interest lies in astronomical instrumentation, especially the following projects: (1) The Ultra-Violet Imaging Telescope (UVIT), for the Indian multi-wavelength mission ASTROSAT (to be launched by ISRO), is currently under development. It consists of three imagers, in the Far-Ultra-Violet (FUV: 130 - 180 nm), the Near-Ultra-Violet (NUV: 200 - 300 nm) and the Visible (VIS: 320-550nm) bands. UVIT can image the sky simultaneously in the above three channels with a field of view of ~28 arcminutes and an angular resolution better than 1.8". In addition, gratings are available in the FUV and the NUV channels for slitless low-resolution spectroscopy. Photon-counting detector systems have been used for each of the 3 channels. Images from the VIS channel are principally used for measuring drift, and to aid the reconstruction of the absolute aspect of the images from all 3 bands through off-line processing on the ground. (2) The Infrared Spectroscopic Imaging Survey (IRSIS) payload, targeted for the Small Satellite Mission of ISRO, aims to carry out low resolution (R~100) spectroscopic measurements in the wavelength range 1.7 to 6.4 micron with seamless coverage, covering a large fraction (~ 50%) of the sky (including the Galactic Plane), with good sensitivity The primary science goals of this project include: (i) Discovery & classification of Brown Dwarfs and M-L-T Dwarfs, probing the faint end of the stellar Initial Mass Function; (ii) Large scale mapping in emission features, especially in the PAH lines at 3.3 & 6.2 micron, via a Galactic Plane survey; (iii) Probing minor bodies of the Solar System, including Asteroids, Comets, and Inter-Planetary Dust; and (iv) a Galactic Bulge survey to study Asymptotic Giant Branch (AGB), Red-Super-Giant (RSG) and Carbon-rich stars. The IRSIS database is expected to provide infrared characterisation of stars, and various types of Solar system bodies. The development of a Laboratory Model of IRSIS is currently in progress. (3) The TIFR Near InfraRed Spectrometer and Imager (TIRSPEC) is based on a 1024 x 1024 HgCdTe focal plane array with imaging and medium resolution (~ 1500) spectroscopic capabilities in the 1 - 2.5 micron wavelength range. TIRSPEC is currently undergoing characterization at the Cassegrain focal plane of the 2-m Himalayan Chandra Telescope (HCT) of the Indian Institute of Astrophysics. It is aimed at studying low temperature

Selected publications:

1. Re-appearance of McNeil's nebula (V1647 Orionis) and its outburst environment. (J. P. Ninan, D. K. Ojha, B. C. Bhatt, S. K. Ghosh et al. 2013, ApJ, 778, 116)

2. Large-scale mapping of the massive star-forming region RCW38 in the [CII] and PAH emission. (H. Kaneda, T. Nakagawa, S.K. Ghosh et al. 2013, A&A, 556, A92)

3. A Multiwavelength Study of Star Formation in the Vicinity of Galactic HII Region Sh2-100. (M. R. Samal, A. K. Pandey, D. K. Ojha, S. K. Ghosh et al. 2010, ApJ, 714, 1015)

4. Infrared Study of the Southern Galactic Star-Forming Regions Associated with IRAS10049-5657 and IRAS10031-5632. (S. Vig, S. K. Ghosh, D. K. Ojha & R. P. Verma, 2008, AJ, 136, 1427)

5. A multiwavelength study of the ultracompact HII region associated with IRAS20178+4046. (A. Tej, S. K. Ghosh et al. 2007, A&A, 468, 1001)

6. Infrared study of the southern Galactic star-forming region associated with IRAS14416-5937. (S. Vig, S. K. Ghosh, D. K. Ojha & R. P. Verma 2007, A&A, 463, 175)

7. Infrared and Radio Study of Star-forming Regions Associated with IRAS19111+1048 and IRAS19110+1045. (S. Vig, S. K. Ghosh et al. 2006, ApJ, 637, 400)

8. Warp signatures of the Galactic disk as seen in mid infrared from Midcourse Space Experiment. (S. Vig, S.K. Ghosh & D.K. Ojha 2005, A&A, 436, 867)

9. Mapping of large scale 158 micron [CII] line emission: Orion A. (B. Mookerjea, S.K. Ghosh et al. 2003, A&A, 404, 569)

10. Spatial distribution of emission in unidentified infrared bands from the Midcourse Space Experiment survey. (S.K. Ghosh & D.K. Ojha 2002, A&A, 388, 326)